1. Field of the Invention
The invention relates to a method and devices for pre-exposing a portion of a filmstrip frame with a latent image in registration with the balance of the frame for exposure within a single use camera. In particular, the invention relates to a method for providing alignment of a latent image within the film frame and identifying the position of the latent image for placing the frame in proper registration within a single use camera.
2. Description of Background Art
Single use camera are well known in the art. They have proven particularly popular for fun photography requiring little more than an "aim and shoot" technique to create pleasing photographs. In an effort to further develop fun and excitement centered around the use of a single use camera, many techniques have been developed for pre-exposing the film loaded within the camera for placing a latent image on a film frame to create a pleasing photograph having the pre-exposed image in juxtaposition with a subject photographed by the single use camera.
U.S. Patent No. 4,310,232 issued to Richard F. Reed on Jan. 12, 1982 discloses a photographic apparatus and method for adding artificial backgrounds. Reed '232 points out that a problem well known in the art is in the alignment of the subject of the second exposure with the unexposed portion of the film frame at the second exposure.
U.S. Pat. No. 4,427,279 issued to Allen Edelstein on Jan. 24, 1984 discloses a solution to the alignment problem including simultaneous exposure of the film frame within the camera.
U.S. Pat. No. 4,655,570 issued to Hal R. Jaffe on Apr. 7, 1987 discloses a camera with a border image producing device having a photograph area and a border area extending completely about the photograph area. The camera includes a template for being placed over a frame of photographic film. An internal light source mounted within the camera exposes one section of each film frame and the camera lens and shutter expose the other section.
U.S. Pat. No. 4,707,106 issued to Bruce K. Johnson, et al. on Nov. 17, 1987 discloses masking portions of the film within a first exposure, then exchanging a mask and exposing the second or other portions.
U.S. Pat. No. 4,827,291 issued to Moshe Guez on May 2, 1989 discloses a photographic aid apparatus photographing a uniformly illuminated object. There is disclosed a method for making superimposed photographs on the same frame of a roll of negative film. Guez '291 discloses masking, exposing within the camera, rewinding the film and providing a different mask and exposing each frame a second time while preventing exposure of the pre-exposed portion of the film.
U.S. Pat. No. 5,111,224 issued to Donald Spector on May 5, 1992 discloses a camera for producing pictures of individuals jointly with characters. The camera produces a picture in which an individual whose picture is taken is seen jointly with a figurative character in such a way as to establish an apparent relationship therebetween. The camera is loaded with a dual track film having a picture track and a parallel guide track. Spector '224 discloses pre-exposing the film to capture an image. The entire film frame is exposed again wherein the first exposure comprised an under exposure and the second a full exposure.
In a camera for making collage photographs, U.S. Pat. No. 4,896,176 issued to Edwin M. Barrett discloses the use of transparency overlays in a self-developing film camera. A flash unit reflects light off of a screen producing an edged design from an overlay located within the camera.
U.S. Pat. No. 5,187,512 issued to George F. Kirkendall on Feb. 16, 1993 discloses a film cassette containing pre-exposed film. During manufacture, each frame of a filmstrip has one portion masked while the frame is exposed to light. The light impinges on a second portion of the frame to form a latent image. The filmstrip is then mounted within a camera where a previously unexposed portion of the frame is exposed to a second image bearing light, while the pre-exposed portion of the frame is masked from the second light. The strip of film is removed from the camera to develop the two latent images as a single photograph. Kirkendall '512 discloses pre-exposing a filmstrip to a single image located within a non-opaque area of a template or mask during manufacturing of the pre-exposed filmstrip.
In summary, pre-exposing a filmstrip is taught in the prior art. In particular, Kirkendall '512 discloses masking a portion of a single use camera aperture frame opening for shielding a portion of the pre-exposed filmstrip having a latent image. However, the art does not disclose a device nor teach a method for pre-exposing a filmstrip for use in a single use camera providing precise alignment between the masking portion and the latent image sufficient to result in a doubly exposed filmstrip having the latent image and subsequent image in proper registration. Prior art devices can have perceptible margin and thus unattractive margin between images.